Apple Watch Series 4 teardown exposes all the big changes

Apple Watch Series 4 brings a lot of changes, but how much has it changed on the inside? Quite a bit, actually -- iFixit has torn down the new smartwatch, and it's clear that this was Apple's opportunity to rethink some of the hidden details. For one, it offers a good look at Series 4's ECG monitoring, including the components in the Digital Crown that complete the circuit. You'll also see a much thinner (if longer) Taptic Engine, a much larger speaker and a smaller battery -- the 44mm Watch pack has 20 percent less capacity than that from the 42mm Series 3. Apple may be counting on the newer processor and other refinements to make up the difference.

There's also a pleasant surprise: the Series 4 is relatively repairable. The insides are "much more thoughtfully laid out" than in the past, iFixit said, and you can replace the battery and screen if you're willing to put in enough effort. You're still unlikely to fix it yourself unless you have the patience and know-how, but there's a distinct possibility it will work. The main obstacles are the preponderance of flex cables and tiny screws that require uncommon tools. Apple is much more comfortable with wearable tech than it was a few years ago, and that's reflected in many aspects of the design.